Indium oxide decorated graphitic carbon nitride/multiwalled carbon nanotubes ternary composite for supercapacitor applications

•A novel ternary composite of In2O3/g-C3N4/MWCNT (GCI) was prepared by a simple one-pot solvothermal method.•The synergistic contribution of the components facilitates the overall electrochemical performance of GCI.•The GCI electrode exhibited a specific capacitance of 1081 F g−1 at 1 A g−1 and a capacitance retention of 97.5 % over 5000 cycles.•The asymmetric supercapacitor fabricated using GCI electrode (GCI//AC) showcased a notable energy density and power density. A hybrid ternary composite In2O3/g-C3N4/MWCNT (GCI) was synthesized by combining three-dimensional In2O3, two-dimensional g-C3N4, and one-dimensional MWCNTs employing a one-pot solvothermal method. The resulting In2O3/g-C3N4/MWCNTs composite leverages the combined benefits of the integration of different dimensionality materials and the synergy between its components. Integrating 1D, 2D, and 3-D materials can create hybrid structures with 3D architectures. It exhibits hierarchical porosity that provides better conductive pathways for ion transport and improves the rate performance. The distinct spatial structure of the composite with short ion diffusion paths maximizes the exposure of the active sites and enhances the conductivity, leading to superior energy storage performance. The electrochemical assessment of the In2O3/g-C3N4/MWCNTs composite exhibited a remarkable specific capacitance of 1081 F g−1 at 1 A g−1 with a commendable capacitance retention of 97.5 % at 3 A g−1 over 5000 cycles. An asymmetric supercapacitor fabricated using In2O3/g-C3N4/MWCNT//AC showcased a notable energy density of 57.5 Wh Kg−1 with an impressive power density of 2760 W Kg−1 at 1 A g−1. The outstanding electrochemical attributes of the fabricated device underscore the potential of the material for future applications in hybrid energy storage systems. [Display omitted]